UWB Positioning Reaches 10 to 30 Centimetre Accuracy Indoors

Ultra-wideband positioning delivers indoor accuracy of 10 to 30 centimetres, substantially sharper than Bluetooth, Wi-Fi round-trip time or RFID can manage. The technology operates across a wide spectrum from 3.1 to 10.6 GHz, and is used for pallet tracking, patient flow, digital car keys and secure access control.

The accuracy difference comes from how the measurement is made rather than from more power or better radios. Bluetooth and RFID positioning infer distance from received signal strength, which varies with orientation, obstruction and reflection, and is therefore an estimate dressed as a measurement. UWB measures time of flight directly using very short pulses, so distance is derived from physics that interference distorts far less.

That distinction determines where each belongs. Room-level accuracy — knowing a tagged item is somewhere in a warehouse aisle — is well served by cheaper technologies. Knowing which of two adjacent pallets is which, or that a key is inside a car rather than just outside it, requires the tighter measurement. The second case is also a security boundary rather than a convenience, which is why the same property that makes UWB accurate makes it resistant to the relay attacks that defeat signal-strength systems.